Android 实现图片的翻转
openkk
13年前
<p>android 实现图片的翻转</p> <pre class="brush:java; toolbar: true; auto-links: false;">Resources res = this.getContext().getResources(); img = BitmapFactory.decodeResource(res, R.drawable.aa); Matrix matrix = new Matrix(); matrix.postRotate(180); /*翻转180度*/ int width = img.getWidth(); int height = img.getHeight(); img_a = Bitmap.createBitmap(img, 0, 0, width, height, matrix, true);</pre> <p></p> <p>然后可以直接把img_a draw到画布上，canvas.drawBitmap(img_a, 10, 10, p);</p> <p>Matrix 是一个处理翻转、缩放等图像效果的重要类</p> <p>Matrix.postScale 可设置缩放比例，默认为1</p> <p>**********************************************************************<br /> android 实现图片的旋转</p> <pre class="brush:java; toolbar: true; auto-links: false;">public class ex04_22 extends Activity{ private ImageView mImageView; private Button btn1,btn2; private TextView mTextView; private AbsoluteLayout layout1; private int ScaleTimes=1,ScaleAngle=1; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); mImageView=(ImageView)findViewById(R.id.myImageView); final Bitmap bmp=BitmapFactory.decodeResource(this.getResources(),R.drawable.ex04_22_1); final int widthOrig=bmp.getWidth(); final int heightOrig=bmp.getHeight(); mImageView.setImageBitmap(bmp); btn1=(Button)findViewById(R.id.myButton1); btn1.setOnClickListener(new OnClickListener(){ public void onClick(View v){ ScaleAngle--; if(ScaleAngle<-60){ ScaleAngle=-60; } int newWidth=widthOrig*ScaleTimes; int newHeight=heightOrig*ScaleTimes; float scaleWidth=((float)newWidth)/widthOrig; float scaleHeight=((float)newHeight)/heightOrig; Matrix matrix=new Matrix(); matrix.postScale(scaleWidth, scaleHeight); matrix.setRotate(5*ScaleAngle); Bitmap resizeBitmap=Bitmap.createBitmap(bmp, 0, 0, widthOrig, heightOrig, matrix, true); BitmapDrawable myNewBitmapDrawable=new BitmapDrawable(resizeBitmap); mImageView.setImageDrawable(myNewBitmapDrawable); } }); btn2=(Button)findViewById(R.id.myButton2); btn2.setOnClickListener(new OnClickListener(){ public void onClick(View v){ ScaleAngle++; if(ScaleAngle>60){ ScaleAngle=60; } int newWidth=widthOrig*ScaleTimes; int newHeight=heightOrig*ScaleTimes; float scaleWidth=((float)newWidth)/widthOrig; float scaleHeight=((float)newHeight)/heightOrig; Matrix matrix=new Matrix(); matrix.postScale(scaleWidth, scaleHeight); matrix.setRotate(5*ScaleAngle); Bitmap resizeBitmap=Bitmap.createBitmap(bmp, 0, 0, widthOrig, heightOrig, matrix, true); BitmapDrawable myNewBitmapDrawable=new BitmapDrawable(resizeBitmap); mImageView.setImageDrawable(myNewBitmapDrawable); } }); }</pre> <p></p> <p>**********************************************************************</p> <p>实现画面淡入淡出效果可以用 ：setAlpha(alpha); <br /> alpha从255，逐渐递减!</p> <p>**********************************************************************</p> <p>如何实现屏幕的滚动效果，这里有两个关键点，一个是实现OnGestureListener，</p> <p>以便在触摸事件发生的时候，被回调。包括按下，滚动等等，按照API文档，</p> <p>需要分两步来实现检测手势行为。</p> <p>1）创建GestureDetector实例</p> <p>2) 在onTouchEvent()方法中调用GestureDetector的onTouchEvent()方法。</p> <p></p> <p>另一个关键点是自己实现一个简单的View，来绘制图片。</p> <p></p> <p>代码如下所示。由于，我们不需要使用layout定义，所以不需要提供xml文件。<br /> 直接在程序里面setContentView()即可。</p> <pre class="brush:java; toolbar: true; auto-links: false;">package com.j2medev; import android.app.Activity; import android.content.Context; import android.content.res.Resources; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.Canvas; import android.graphics.Paint; import android.os.Bundle; import android.view.GestureDetector; import android.view.MotionEvent; import android.view.View; import android.view.ViewGroup; import android.view.GestureDetector.OnGestureListener; public class HorizontalScroll extends Activity implements OnGestureListener { private static final int X_MAX = 800; private static final int Y_MAX = 600; private int scrollX = 0; private int scrollY = 0; MyView main; Bitmap bmp; Bitmap adapt; Resources res; Paint paint; GestureDetector gestureScanner; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); gestureScanner = new GestureDetector(this); paint = new Paint(); res = getResources(); bmp = BitmapFactory.decodeResource(res, R.drawable.arc); adapt = Bitmap.createBitmap(bmp); main = new MyView(this); setContentView(main, new ViewGroup.LayoutParams(800, 600)); } @Override public boolean onTouchEvent(MotionEvent me) { return gestureScanner.onTouchEvent(me); } public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) { main.handleScroll(distanceX, distanceY); return true; } public boolean onDown(MotionEvent e) { return true; } public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) { return true; } public void onLongPress(MotionEvent e) { } public void onShowPress(MotionEvent e) { } public boolean onSingleTapUp(MotionEvent e) { return true; } // ////////////////// // ///////////////// // //////////////// class MyView extends View { public MyView(Context context) { super(context); } @Override protected void onDraw(Canvas canvas) { canvas.drawBitmap(adapt, -scrollX, -scrollY, paint); } public void handleScroll(float distX, float distY) { // X-Axis //////////////////////////////// if (distX > 6.0) { if (scrollX < 460) { scrollX += 15; } } else if (distX < -6.0) { if (scrollX >= 15) { scrollX -= 15; } } // ////////////////////////////////////////// // Y-AXIS ////////////////////////////////// if (distY > 6.0) { if (scrollY < 100) { scrollY += 15; } } else if (distY < -6.0) { if (scrollY >= 15) { scrollY -= 15; } } // ////////////////////////////////////////// // // if ((scrollX <= 480) && (scrollY <= 120)) { // adapt = Bitmap.createBitmap(bmp, scrollX, scrollY, 320, 480); // invalidate(); // } invalidate(); } } }</pre> <p></p> <p>**********************************************************************</p> <p>教你在谷歌Android平台中处理图片</p> <p>操作图像像素</p> <p>现在你可以对单独的像素进行处理了。通过使用android.graphics.Bitmap API中的</p> <p>getPixels，可以加载像素到一个整数数组中。在本文例子中，你将按照一定规则对每一<br /> <br /> 个像素实现着色。经过这个处理后，所有的像素将被转化为一个范围在0到255的字节码。<br /> <br /> android.graphics.Bitmap API中的setPixels则用来加载这个整数数组到一个图像中。<br /> <br /> 最后一步是通过ImageView变量mIV来更新屏幕。以下是实现这个染色过程的代码片段。</p> <pre class="brush:java; toolbar: true; auto-links: false;">private void TintThePicture(int deg) { int[] pix = new int[picw * pich]; mBitmap.getPixels(pix, 0, picw, 0, 0, picw, pich); int RY, GY, BY, RYY, GYY, BYY, R, G, B, Y; double angle = (3.14159d * (double)deg) / 180.0d; int S = (int)(256.0d * Math.sin(angle)); int C = (int)(256.0d * Math.cos(angle)); for (int y = 0; y < pich; y++) for (int x = 0; x < picw; x++) { int index = y * picw + x; int r = (pix[index] >> 16) & 0xff; int g = (pix[index] >> 8) & 0xff; int b = pix[index] & 0xff; RY = ( 70 * r - 59 * g - 11 * b) / 100; GY = (-30 * r + 41 * g - 11 * b) / 100; BY = (-30 * r - 59 * g + 89 * b) / 100; Y = ( 30 * r + 59 * g + 11 * b) / 100; RYY = (S * BY + C * RY) / 256; BYY = (C * BY - S * RY) / 256; GYY = (-51 * RYY - 19 * BYY) / 100; R = Y + RYY; R = (R < 0) ? 0 : ((R > 255) ? 255 : R); G = Y + GYY; G = (G < 0) ? 0 : ((G > 255) ? 255 : G); B = Y + BYY; B = (B < 0) ? 0 : ((B > 255) ? 255 : B); pix[index] = 0xff000000 | (R << 16) | (G << 8) | B; } Bitmap bm = Bitmap.createBitmap(picw, pich, false); bm.setPixels(pix, 0, picw, 0, 0, picw, pich); // Put the updated bitmap into the main view mIV.setImageBitmap(bm); mIV.invalidate(); mBitmap = bm; pix = null; }</pre> <p></p> <p>**********************************************************************</p> <p>android 图片的放大和缩小</p> <pre class="brush:java; toolbar: true; auto-links: false;">public class ex04_22 extends Activity{ private ImageView mImageView; private Button btn1,btn2; private TextView mTextView; private AbsoluteLayout layout1; private Bitmap bmp; private int id=0; private int displayWidth,displayHeight; private float scaleWidth=1,scaleHeight=1; private final static String filename="/data/data/ex04_22.lcs/ex04_22_2.png"; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); //取得屏幕分辨率 DisplayMetrics dm=new DisplayMetrics(); getWindowManager().getDefaultDisplay().getMetrics(dm); displayWidth=dm.widthPixels; displayHeight=dm.heightPixels-80; bmp=BitmapFactory.decodeResource(this.getResources(),R.drawable.ex04_22_1); layout1=(AbsoluteLayout)findViewById(R.id.layout1); mImageView=(ImageView)findViewById(R.id.myImageView); btn1=(Button)findViewById(R.id.myButton1); btn1.setOnClickListener(new OnClickListener(){ public void onClick(View v){ small(); } }); btn2=(Button)findViewById(R.id.myButton2); btn2.setOnClickListener(new OnClickListener(){ public void onClick(View v){ big(); } }); } private void small(){ //获得Bitmap的高和宽 int bmpWidth=bmp.getWidth(); int bmpHeight=bmp.getHeight(); //设置缩小比例 double scale=0.8; //计算出这次要缩小的比例 scaleWidth=(float)(scaleWidth*scale); scaleHeight=(float)(scaleHeight*scale); //产生resize后的Bitmap对象 Matrix matrix=new Matrix(); matrix.postScale(scaleWidth, scaleHeight); Bitmap resizeBmp=Bitmap.createBitmap(bmp, 0, 0, bmpWidth, bmpHeight, matrix, true); if(id==0){ layout1.removeView(mImageView); } else{ layout1.removeView((ImageView)findViewById(id)); } id++; ImageView imageView=new ImageView(this); imageView.setId(id); imageView.setImageBitmap(resizeBmp); layout1.addView(imageView); setContentView(layout1); btn2.setEnabled(true); } private void big(){ //获得Bitmap的高和宽 int bmpWidth=bmp.getWidth(); int bmpHeight=bmp.getHeight(); //设置缩小比例 double scale=1.25; //计算出这次要缩小的比例 scaleWidth=(float)(scaleWidth*scale); scaleHeight=(float)(scaleHeight*scale); //产生resize后的Bitmap对象 Matrix matrix=new Matrix(); matrix.postScale(scaleWidth, scaleHeight); Bitmap resizeBmp=Bitmap.createBitmap(bmp, 0, 0, bmpWidth, bmpHeight, matrix, true); if(id==0){ layout1.removeView(mImageView); } else{ layout1.removeView((ImageView)findViewById(id)); } id++; ImageView imageView=new ImageView(this); imageView.setId(id); imageView.setImageBitmap(resizeBmp); layout1.addView(imageView); setContentView(layout1); if(scaleWidth*scale*bmpWidth>displayWidth||scaleHeight*scale*scaleHeight>displayHeight){ btn2.setEnabled(false); } } }</pre> <p></p> <p>xml文件</p> <pre class="brush:xml; toolbar: true; auto-links: false;"><?xml version="1.0" encoding="utf-8"?> <AbsoluteLayout android:id="@+id/layout1" android:layout_width="fill_parent" android:layout_height="fill_parent" xmlns:android="http://schemas.android.com/apk/res/android" > <ImageView android:id="@+id/myImageView" android:layout_width="200px" android:layout_height="150px" android:src="@drawable/ex04_22_1" android:layout_x="0px" android:layout_y="0px" > </ImageView> <Button android:id="@+id/myButton1" android:layout_width="90px" android:layout_height="60px" android:text="缩小" android:textSize="18sp" android:layout_x="20px" android:layout_y="372px" > </Button> <Button android:id="@+id/myButton2" android:layout_width="90px" android:layout_height="60px" android:text="放大" android:textSize="18sp" android:layout_x="210px" android:layout_y="372px" > </Button> </AbsoluteLayout></pre> <p></p> <p>*********************************************************************</p> <p>android 图片透明度处理代码</p> <pre class="brush:java; toolbar: true; auto-links: false;">public static Bitmap setAlpha(Bitmap sourceImg, int number) { int[] argb = new int[sourceImg.getWidth() * sourceImg.getHeight()]; sourceImg.getPixels(argb, 0, sourceImg.getWidth(), 0, 0,sourceImg.getWidth(), sourceImg.getHeight());// 获得图片的ARGB值 number = number * 255 / 100; for (int i = 0; i < argb.length; i++) { argb = (number << 24) | (argb & 0x00FFFFFF);// 修改最高2位的值 } sourceImg = Bitmap.createBitmap(argb, sourceImg.getWidth(), sourceImg.getHeight(), Config.ARGB_8888); return sourceImg; }</pre>